Fig. 3.

L. panamensis promastigotes and amastigotes induce TNF-α production in a dose-dependent manner and activate macrophages through TLR-dependent signaling. (A) TNF-α production by WT macrophages exposed to increasing parasite-to-cell ratios, using opsonized promastigotes or amastigotes, specific TLR ligands (hatched bars), or no treatment. (B) MyD88/TRIF^−/− cells were infected at a 100:1 parasite-to-macrophage ratio. Data are representative of three independent experiments and are expressed as means ± SEM. *, P < 0.05.